Computed Tomography (CT Scan) also referred to as Computer Aided Tomography (CAT Scan) combines x-rays and computers to image the body. Just about any body part can be imaged (abdomen and pelvis, chest, brain, blood vessels, neck) and typically CT scans are done to look for injuries, tumors, stones, and other disease. A x-ray unit inside a shallow, donut shaped machine produces x-rays, which are collected on the other side of the machine to create cross-sectional image of the body part being examined.
Sometimes radiographic contrast or "x-ray dye" may be needed to better visualize the body part being examined. The dye is injected into a vein in the arm to “highlight” blood vessels and other vascular structures within the body. For CT scan of the abdomen and pelvis, oral contrast called barium may be given at least one hour prior to the scan to highlight the stomach and intestinal tract.
Indications For a CT Scan
A CT scan can evaluate for liver disease, jaundice, abdominal pain, and can determine whether cancer has spread from another part of the body. The scan can look for and bleeding in the liver and/or spleen. CT can evaluate inflammation of the pancreas and gallbladder, look for diverticulitis, polyps, and for abscess or infection. A doctor may order a CT for hematuria (blood in the urine), difficult/painful urination, bloody stools, changes in bowel habits, chronic/acute abdominal pain and/or fever, appendicitis, enlarged lymph nodes, evaluate for aneurysm, evaluate blood vessels of upper/lower extremities and head/neck for narrowing or blockage.
A CT scan can evaluate for pneumonia, lung nodules and/or masses, evaluate for COPD (chronic obstructive pulmonary disease) such as emphysema, evaluate for aneurysm or stenosis (narrowing), chronic cough, fever, chest pain, to evaluate for blood clots within the blood vessels of the lungs.
CT scan is commonly used to evaluate the brain for stroke and intracranial bleeding (hemorrhage). It can evaluate for brain and neck masses, look at the blood vessels in the brain and neck, and evaluate for skull and cervical (neck) spine fractures.
CT scan can be used to evaluate any bony anatomy and look for fracture in just about any part of the body, from the top of the skull to the base of the feet, including the entire spine and pelvis, the face and any extremities (arms and legs).
CT scan can also be used to evaluate for disc herniations (slipped and torn discs in the back and neck).
A CT scan can be used to guide a needle or catheter to the area of the body being examined. An Interventional Radiologist, who is a specially trained doctor that can accurately obtain a sample of tissue or fluid for laboratory analysis, performs this procedure.
A CT scan performed specifically to evaluate the blood vessels. It is a less invasive alternative to conventional angiography and involves no sedation. It involves to administration of “x-ray dye” through a vein in the arm, and can image to brain, neck, chest, abdomen/pelvis, and extremities.
A CT scan performed to evaluate the colon or large intestine. This is a less invasive radiology imaging alternative to conventional colonoscopy involving no sedation. Is primarily performed to evaluate for polyps and diverticulitis.